The health status and yield of winter rapeseed (Brassica napus L.) grown in monoculture and in crop rotation under different agricultural production systems

Abstract

ABSTRACTIn a field experiment, winter rapeseed was grown in 5-year monoculture and in crop rotation (winter rapeseed, winter wheat, field peas, spring wheat and winter rapeseed). Two open-pollinated cultivars (Californium and Castille) and one hybrid cultivar (Nelson) were compared in systems with three levels of agricultural inputs, low input, medium input and high input, characterized by different rates of nitrogen and sulfur fertilization and pesticide use. The severity of sclerotinia rot (Sclerotinia sclerotiorum) and verticillium wilt (Verticillium spp.) on plants, dark spot (Alternaria spp.) and grey mold (Botrytis cinerea) on leaves and pods, as well as dry rot (Phoma lingam) on stems was evaluated during the growing season. The yield of winter rapeseed was calculated. Rapeseed grown after a 4-year break was characterized by less severe symptoms of dark spot on leaves and dry rot on stems, but more severe symptoms of grey mold on leaves and pods. The severity of dark spots on rapeseed pods (in crop rotation) was reduced with an increase in agricultural inputs. Cultivars Californium and Nelson were generally rarely infected by Verticillium spp., their leaves were less infected by Alternaria spp. and stems by Phoma spp. Nelson was the highest-yielding cultivar.